Questions

Refractive Index of glass with respect to water can be calculated by 

(Refractive Index of glass with respect to air) × (1/Refractive Index of water with respect to air)

We know that,

Refractive Index of glass with respect to air = 4/3

Refractive index of water with respect to air = 3/2

Hence, Refractive Index of glass with respect to water = (4/3) x (2/3) = 8/9.

It refers to the possibility for an investor to experience  losses due to  factors that affect the overall performance of the financial markets. Market risk cannot be eliminated through diversification, though it can be hedged against. The sources of market risk include natural disasters, recessions, political turmoil, changes in interest rates and terrorist attacks.

Cognitive psychology is the branch of psychology that studies study internal processes that include perception, attention, language, memory, and thinking.

Cognitive psychology focuses on the way people process information.

Here ‘passed each other’ means crossed each other’s path. No preposition is required by ‘passed’.